CN105714016B - Low-carbon, low-sulfur and low nitrogen steel are manufactured at low cost using traditional steelmaking equipment - Google Patents
Low-carbon, low-sulfur and low nitrogen steel are manufactured at low cost using traditional steelmaking equipment Download PDFInfo
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 339
- 239000010959 steel Substances 0.000 title claims abstract description 339
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 166
- 229910052717 sulfur Inorganic materials 0.000 title claims description 21
- 239000011593 sulfur Substances 0.000 title claims description 19
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 title description 44
- 229910052757 nitrogen Inorganic materials 0.000 title description 22
- 238000009628 steelmaking Methods 0.000 title description 6
- 239000000203 mixture Substances 0.000 claims abstract description 247
- 238000000034 method Methods 0.000 claims abstract description 227
- 239000001301 oxygen Substances 0.000 claims abstract description 95
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 95
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 93
- 238000010079 rubber tapping Methods 0.000 claims abstract description 93
- 238000002844 melting Methods 0.000 claims abstract description 60
- 230000008018 melting Effects 0.000 claims abstract description 60
- 238000004519 manufacturing process Methods 0.000 claims abstract description 56
- 238000005261 decarburization Methods 0.000 claims abstract description 41
- 230000004907 flux Effects 0.000 claims abstract description 34
- 238000006477 desulfuration reaction Methods 0.000 claims abstract description 33
- 230000023556 desulfurization Effects 0.000 claims abstract description 32
- 239000002893 slag Substances 0.000 claims abstract description 28
- 150000001875 compounds Chemical class 0.000 claims abstract description 21
- 238000005266 casting Methods 0.000 claims abstract description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 96
- 230000008569 process Effects 0.000 claims description 76
- 238000007872 degassing Methods 0.000 claims description 45
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 43
- 239000004411 aluminium Substances 0.000 claims description 24
- 229910052782 aluminium Inorganic materials 0.000 claims description 24
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 24
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 21
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 21
- 239000004571 lime Substances 0.000 claims description 21
- 238000003756 stirring Methods 0.000 claims description 20
- 239000000654 additive Substances 0.000 claims description 17
- 230000000996 additive effect Effects 0.000 claims description 16
- 238000010891 electric arc Methods 0.000 claims description 10
- XFWJKVMFIVXPKK-UHFFFAOYSA-N calcium;oxido(oxo)alumane Chemical compound [Ca+2].[O-][Al]=O.[O-][Al]=O XFWJKVMFIVXPKK-UHFFFAOYSA-N 0.000 claims description 8
- 229910000514 dolomite Inorganic materials 0.000 claims description 7
- 239000010459 dolomite Substances 0.000 claims description 7
- 229910001021 Ferroalloy Inorganic materials 0.000 claims description 4
- 229910015136 FeMn Inorganic materials 0.000 claims description 2
- 230000003647 oxidation Effects 0.000 claims description 2
- 238000007254 oxidation reaction Methods 0.000 claims description 2
- 239000005864 Sulphur Substances 0.000 description 34
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 14
- 229910045601 alloy Inorganic materials 0.000 description 13
- 239000000956 alloy Substances 0.000 description 13
- 239000004744 fabric Substances 0.000 description 10
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 8
- 229910002091 carbon monoxide Inorganic materials 0.000 description 8
- 239000003795 chemical substances by application Substances 0.000 description 8
- 229910052786 argon Inorganic materials 0.000 description 7
- 238000007796 conventional method Methods 0.000 description 7
- 238000009826 distribution Methods 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 6
- 238000002360 preparation method Methods 0.000 description 6
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 238000004090 dissolution Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000004615 ingredient Substances 0.000 description 4
- 230000003287 optical effect Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 238000011068 loading method Methods 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 230000032258 transport Effects 0.000 description 3
- 229910001339 C alloy Inorganic materials 0.000 description 2
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 2
- 235000003140 Panax quinquefolius Nutrition 0.000 description 2
- 240000005373 Panax quinquefolius Species 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 229910052681 coesite Inorganic materials 0.000 description 2
- 229910052593 corundum Inorganic materials 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- -1 oxygen ion Chemical class 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- 229910001845 yogo sapphire Inorganic materials 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 229910000655 Killed steel Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 238000006392 deoxygenation reaction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000000222 hyperoxic effect Effects 0.000 description 1
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/52—Manufacture of steel in electric furnaces
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Manufacture the method with the steel lower than 0.035 weight % low-carbon, it includes the following steps: to prepare the furnace melting steel compositions that temperature reaches tapping temperature in converter, the tapping temperature is temperature needed for carrying out desulfurization in VTD, opening tapping oxygen level is the melting steel compositions of 600~1120ppm to ladle, ladle is supplied to slag making compound to form clinker to cover the melting steel compositions in ladle, melting steel compositions in ladle are transported to VTD, it is lower than 650 millibars by being evacuated in VTD come to melting steel compositions progress decarburization, after decarburization, one or more deoxidiers are added into melting steel compositions and deoxidation is carried out to melting steel compositions, after deoxidation, one or more flux compounds are added to carry out desulfurization to melting steel compositions, and Casting melting steel compositions are to form the steel having lower than 0.035 weight % low-carbon.
Description
The application is that international filing date is August in 2009 3, application No. is 200980138838.4, entitled " benefits
Manufacture low-carbon, low-sulfur and low nitrogen steel at low cost with traditional steelmaking equipment " application for a patent for invention divisional application.
Background and summary of the invention
Certain shaped steel combination objects need relatively low content of carbon (being lower than 0.035%), nitrogen (being lower than 50ppm) and sulphur (low
In 30ppm).In the past, the method for preparing these low-carbons and low-sulfur steel is needed using in converter and degasification furnace (degasser)
In process combination.Existing method is related to reducing the carbon level of steel compositions in converter (such as electric arc furnaces (EAF)),
Alloy addition (alloy addition) is prepared in tapping process (tapping process) to carry out desulfurization and the alloy of steel
Change, and steel is then shipped for degasification furnace, such as vacuum tank degasification furnace (vacuum tank degasser) (VTD).In this way
Processing route it is simple and quite directly.
In the past, in order to obtain the steel compositions for meeting above-mentioned industrial level, (it is, for example, less than with low-down carbon level
0.025%) steel is tapped in converter.Before tapping, dissolved oxygen levels relevant to these low carbon contents exist in stove
1200ppm~1400ppm order of magnitude.When degasification furnace and stove have a distance, steel has needed since about 1700 DEG C of tappings
The temperature loss during degasification furnace is transported in compensation.In tapping process, steel is by aluminium and ferrosilicon (FeSi) deoxidation.It is also added into
Lime and aluminium dross are to generate liquid, deoxidation, desulfurization clinker.Using these additives, in being transported to degasification furnace
In the process, desulphurization reaction occurs in ladle (ladle).Aluminium, lime, calcium aluminate and white clouds are further added in degasification furnace
Stone lime, so that it is guaranteed that removing required sulphur in degassing circulation.Although using aluminium as main deoxidier, these steel groups
Closing object is industrially considered as silicon killed steel.
Existing method has the disadvantage that the deterioration including the refractory material to converter is high.Needed for before converter tapping
Raised tapping temperature and elevated oxygen level can have a negative impact for the production capacity in furnace.High temperature and hyperoxic conditions make
The FeO amount obtained in clinker at high temperature is more, causes excessive furnace wall refractory deterioration.Although using whitewashing to oven refractory
It is repaired, this off-time that can still result in stove increases.In clinker high FeO content also result in steel-making efficiency it is lower,
This is because losing more iron units in clinker.
Existing method is also needed using low-carbon alloy and additive in the subsequent processing of entire converter, to keep low
Carbon level is lower than 0.035 weight %.Low-carbon alloy ingredient (such as low-carbon FeMn) is needed to provide required ingredient, thus will not
Damage the final carbon content in steel.Recently, the price of low carbon ferroalloy (carbon ferro-alloy) obviously increases, to lead
Cause this method that can not economically produce such mild steel.In addition, the carbon amounts reduced in steel compositions in converter needs volume
Outer decarburization time, this can also negatively affect the production capacity in converter.Due to more elevated oxygen level, it is therefore desirable to more silicon
Come to carry out deoxidation to steel compositions with aluminium, be further increased so as to cause cost.There is still a need for reduce low-carbon, low nitrogen and low-sulfur steel
Production cost.
Applicants have found that manufacture mild steel alternative approach, this method avoid using low carbon ferroalloy and produce
Steel has the low-carbon lower than 0.035 weight %, and the method reduce the deteriorations to refractory material, and increase steel-making efficiency.
Disclosed herein is the methods that manufacture has the steel lower than 0.035 weight % low-carbon, and this method comprises the following steps:
(a) prepare furnace melting steel compositions (a heat of molten that temperature reaches tapping temperature in converter
Steel composition), which is temperature needed for carrying out desulfurization in vacuum tank degasification furnace,
(b) the melting steel compositions that tapping oxygen level is 600~1120ppm are opened to ladle,
(c) ladle is provided with slag making compound (slag forming compound) to form clinker to cover and contain
Melting steel compositions in steel drum,
(d) the melting steel compositions in ladle are transported to vacuum tank degasification furnace,
(e) decarburization is carried out to melting steel compositions by being evacuated to lower than 650 millibars in vacuum tank degasification furnace,
(f) after decarburization, one or more deoxidiers are added into melting steel compositions and melting steel compositions are carried out
Deoxidation,
(g) after deoxidation, add one or more flux compounds (flux compound) with to melting steel compositions into
Row desulfurization, and
(i) casting melting steel compositions are to form the steel having lower than 0.035 weight % low-carbon.
It, can be by adding free oxygen into melting steel compositions come to the molten steel through decarburization and deoxidation before casting
Composition is reoxidized, so that horizontal is that 20~70ppm and total oxygen content are at least 70ppm, and then connect in double roller
Casting melting steel compositions are in casting machine (twin roll caster) to form the steel having lower than 0.035 weight % low-carbon
Band.
In tapping step, the sulfur content in steel compositions can be 0.02 weight of weight %~0.06 %.In tapping step
In, the carbon amounts in steel compositions can be lower than for the nitrogen quantity in 0.02 weight of weight %~0.05 % and steel compositions
0.005 weight %.In addition, the step of preparing furnace melting steel compositions can carry out in electric arc furnaces.
It can be in 1600 DEG C~1650 DEG C of temperature, or in 1650 DEG C~1700 DEG C of temperature, or 1700 DEG C~1750
DEG C temperature open tapping step.
It can be taken off at 1~650 millibar or 350~550 millibars, or under vacuum level equal to or less than 530 millibars
Carbon step.
Before decarbonation process, the method for preparing the steel for having low-carbon lower than 0.035 weight % can also include following step
It is rapid:
(i) melting steel compositions of the stirring in the ladle of vacuum tank degasification furnace,
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded,
(iii) provide process model (process model), the process model be associated with steel compositions in oxygen and carbon amounts with
Steel compositions reach the decarburization time of the carbon amounts of needs；And
(iv) amount based on the oxygen and carbon that detect in steel compositions, determines decarburization time using process model.
Alternatively or additionally, before decarbonation process, preparing has the method for the steel lower than 0.035 weight % low-carbon can be with
Further comprise following steps:
(i) steel compositions of the stirring in the ladle of vacuum tank degasification furnace
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded,
(iii) provide process model, the process model be associated with steel compositions in oxygen and carbon amount with to steel compositions into
The amount of deoxidation additive needed for row deoxidation, and
(iv) amount based on the oxygen and carbon that detect in steel compositions, deoxidation in steel compositions is determined using process model
The amount of additive.
The step of one or more flux compounds are added can be related to being added selected from lime, aluminium, calcium aluminate, dolomite stone
One or more compounds of ash and fero-manganesesilicon.
Further, alternatively or additionally, before decarbonation process, preparing has the steel lower than 0.035 weight % low-carbon
Method may further include following steps:
(i) steel compositions of the stirring in the ladle of vacuum tank degasification furnace
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded,
(iii) process model is provided, the oxygen and carbon amounts which is associated in steel compositions are carried out with to steel compositions
The amount of flux component needed for desulfurization and price based on flux component can select one or more flux components；And
(iv) amount based on the oxygen and carbon that detect in steel compositions, the selection of flux component is determined using process model
With their amount.
The invention also includes:
1. manufacturing the method with the steel lower than 0.035 weight % low-carbon comprising following steps:
(a) in converter, prepare the furnace melting steel compositions that temperature reaches tapping temperature, which is vacuum tank
Temperature needed for carrying out desulfurization in degasification furnace,
(b) the melting steel compositions that tapping oxygen level is 600~1120ppm are opened to ladle,
(c) it is supplied to ladle and the melting steel compositions in ladle is covered to form clinker with slag making compound,
(d) the melting steel compositions in ladle are transported to vacuum tank degasification furnace,
(e) decarburization is carried out to melting steel compositions by being evacuated to lower than 650 millibars in vacuum tank degasification furnace,
(f) after decarburization, one or more deoxidiers are added into melting steel compositions and melting steel compositions are carried out
Deoxidation,
(g) after deoxidation, one or more flux compounds are added to carry out desulfurization to melting steel compositions, and
(i) casting melting steel compositions are to form the steel having lower than 0.035 weight % low-carbon.
2. manufacture described in 1 has the method for the steel lower than 0.035 weight % low-carbon, wherein the steel in tapping step
Carbon amounts in composition is 0.02%~0.05 weight %.
3. manufacture described in 1 or 2 has the method for the steel lower than 0.035 weight % low-carbon, wherein prepare furnace molten steel
The step of composition, carries out in electric arc furnaces.
4. manufacture described in any one of above-mentioned item has the method for the steel lower than 0.035 weight % low-carbon, wherein decarburization
Step is in 1~650 millibar of vacuum level.
5. manufacture described in 4 has the method for the steel lower than 0.035 weight % low-carbon, wherein decarbonation process is in 350
~550 millibars of vacuum level.
6. manufacture described in any one of above-mentioned item has the method for the steel lower than 0.035 weight % low-carbon, wherein be added
The aluminium of requirement is added in the vacuum level that the step of one or more deoxidiers is included in 530~1000 millibars.
7. manufacture described in any one of above-mentioned item has the method for the steel lower than 0.035 weight % low-carbon, further include
Following steps: after desulfurization, 1~2.5 millibar is evacuated to except denitrification.
8. manufacture described in any one of above-mentioned item has the method for the steel lower than 0.035 weight % low-carbon, wherein be added
The step of one or more flux compounds includes that one kind selected from lime, aluminium, calcium aluminate, dolomite lime and fero-manganesesilicon is added
Or multiple compounds.
9. manufacture described in any one of above-mentioned item has the method for the steel lower than 0.035 weight % low-carbon, wherein going out
In steel step, the sulfur content in steel compositions is 0.02%~0.06 weight %.
10. manufacture described in any one of above-mentioned item has the method for the steel lower than 0.035 weight % low-carbon, further include
Following step before decarbonation process:
(i) melting steel compositions of the stirring in the ladle of vacuum tank degasification furnace,
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded,
(iii) process model is provided, the oxygen and carbon amounts and steel compositions in process model association steel compositions, which reach, to be needed
Decarburization time needed for the carbon amounts wanted；And
(iv) amount based on the oxygen and carbon that detect in steel compositions, determines decarburization time using process model.
11. manufacture described in any one of 1~9 has the method for the steel lower than 0.035 weight % low-carbon, further include
Following step before decarbonation process:
(i) steel compositions of the stirring in the ladle of vacuum tank degasification furnace
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded,
(iii) provide process model, the process model be associated with steel compositions in oxygen and carbon amount with to steel compositions into
The amount of deoxidation additive needed for row deoxidation, and
(iv) amount based on the oxygen and carbon that detect determines deoxidation additive in steel compositions using process model
Amount.
12. manufacture described in any one of 1~9 has the method for the steel lower than 0.035 weight % low-carbon, further include
Following step before decarbonation process:
(i) steel compositions of the stirring in the ladle of vacuum tank degasification furnace
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded；
(iii) process model is provided, the oxygen and carbon amounts which is associated in steel compositions are carried out with to steel compositions
The amount of flux component needed for desulfurization and price based on flux component can select one or more flux components；And
(iv) amount based on the oxygen and carbon that detect, determined using process model flux component selection and they
Amount.
13. manufacture described in any one of above-mentioned item has the method for the steel lower than 0.035 weight % low-carbon, wherein
1600 DEG C~1650 DEG C of temperature opens tapping step.
14. manufacture described in any one of 1~12 has the method for the steel lower than 0.035 weight % low-carbon, wherein
1650 DEG C~1700 DEG C of temperature opens tapping step.
15. manufacture described in any one of 1~12 has the method for the steel lower than 0.035 weight % low-carbon, wherein
1700 DEG C~1750 DEG C of temperature opens tapping step.
16. manufacturing the method with the steel lower than 0.035 weight % low-carbon comprising following steps:
(a) prepare the furnace melting steel compositions that temperature reaches tapping temperature in converter, which is vacuum tank
Temperature needed for carrying out desulfurization in degasification furnace,
(b) the melting steel compositions that tapping oxygen level is 600~1120ppm are opened to ladle,
(c) it is supplied to ladle and the melting steel compositions in ladle is covered to form clinker with slag making compound,
(d) the melting steel compositions in ladle are transported to vacuum tank degasification furnace,
(e) decarburization is carried out to melting steel compositions by being evacuated to lower than 650 millibars in vacuum tank degasification furnace,
(f) after decarburization, one or more deoxidiers are added into melting steel compositions and melting steel compositions are carried out
Deoxidation,
(g) after deoxidation, add one or more flux compounds with to melting steel compositions carry out desulfurization,
(i) free oxygen is added into melting steel compositions until level is that 20~70ppm and total oxygen content are at least
70ppm, and
(j) then casting melting steel compositions are low lower than 0.035 weight % to which formation has in double-roller continuous casting machine
The steel band of carbon.
17. manufacture described in 16 has the method for the steel lower than 0.035 weight % low-carbon, wherein in tapping step
Carbon amounts in steel compositions is 0.02%~0.05 weight %.
18. manufacture described in 16 or 17 has the method for the steel lower than 0.035 weight % low-carbon, wherein it is molten to prepare furnace
The step of melting steel compositions carries out in electric arc furnaces.
19. manufacture described in any one of 16~18 has the method for the steel lower than 0.035 weight % low-carbon, wherein
Decarbonation process is in 1~650 millibar of vacuum level.
20. manufacture described in any one of 16~19 has the method for the steel lower than 0.035 weight % low-carbon, wherein
Decarbonation process is in 350~550 millibars of vacuum level.
21. manufacture described in any one of 16~20 has the method for the steel lower than 0.035 weight % low-carbon, wherein
The aluminium of requirement is added in the vacuum level that the step of one or more deoxidiers are added is included in 530~1000 millibars.
22. manufacture described in any one of 16~21 has the method for the steel lower than 0.035 weight % low-carbon, also wrap
It includes following steps: after desulfurization, being evacuated to 1~2.5 millibar except denitrification.
23. manufacture described in any one of 16~22 has the method for the steel lower than 0.035 weight % low-carbon, wherein
The step of one or more flux compounds are added includes being added selected from lime, aluminium, calcium aluminate, dolomite lime and fero-manganesesilicon
One or more compounds.
24. manufacture described in any one of 16~23 has the method for the steel lower than 0.035 weight % low-carbon, wherein
In tapping step, the sulfur content in steel compositions is 0.02%~0.06 weight %.
25. manufacture described in any one of 16~24 has the method for the steel lower than 0.035 weight % low-carbon, also wrap
Include the following step before decarbonation process:
(i) melting steel compositions of the stirring in the ladle of vacuum tank degasification furnace,
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded,
(iii) process model is provided, the oxygen and carbon amounts and steel compositions in process model association steel compositions, which reach, to be needed
Decarburization time needed for the carbon amounts wanted；And
(iv) amount based on the oxygen and carbon that detect in steel compositions, determines decarburization time using process model.
26. manufacture described in any one of 16~24 has the method for the steel lower than 0.035 weight % low-carbon, also wrap
Include the following step before decarbonation process:
(i) steel compositions of the stirring in the ladle of vacuum tank degasification furnace
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded,
(iii) provide process model, the process model be associated with steel compositions in oxygen and carbon amount with to steel compositions into
The amount of deoxidation additive needed for row deoxidation, and
(iv) amount based on the oxygen and carbon that detect determines deoxidation additive in steel compositions using process model
Amount.
27. manufacture described in any one of 16~24 has the method for the steel lower than 0.035 weight % low-carbon, also wrap
Include the following step before decarbonation process:
(i) steel compositions of the stirring in the ladle of vacuum tank degasification furnace
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded；
(iii) process model is provided, the oxygen and carbon amounts which is associated in steel compositions are carried out with to steel compositions
The amount of flux component needed for desulfurization and price based on flux component can select one or more flux components；And
(iv) amount based on the oxygen and carbon that detect, determined using process model flux component selection and they
Amount.
28. manufacture described in any one of 16~27 has the method for the steel lower than 0.035 weight % low-carbon, wherein
Tapping step is opened in 1600 DEG C~1650 DEG C of temperature.
29. manufacture described in any one of 16~27 has the method for the steel lower than 0.035 weight % low-carbon, wherein
Tapping step is opened in 1650 DEG C~1700 DEG C of temperature.
30. manufacture described in any one of 16~27 has the method for the steel lower than 0.035 weight % low-carbon, wherein
Tapping step is opened in 1700 DEG C~1750 DEG C of temperature.
Detailed description of the invention
Fig. 1 is the general flowchart for producing the method for low-carbon, low nitrogen and low-sulfur steel；
Fig. 2 is the figure for showing the sulfur content of the one heat steel (heats) into vacuum tank degasification furnace using existing method；
Fig. 3 is to show one but not the only one reality compared using existing method and published method of the present invention
The figure of the oxygen distribution during arc furnace tapping when applying mode；
Fig. 4 is that the FeO in the electric arc furnaces clinker shown when comparing using existing method and published method of the present invention is distributed
Figure；
Fig. 5 is arc furnace tapping mistake when showing the embodiment compared using existing method and published method of the present invention
The figure of steel Temperature Distribution in journey；
It is when Fig. 6 is the embodiment using existing method and published method of the present invention, will be before arc furnace tapping process
The figure that is compared with the carbon amounts after tapping of oxygen amount；
Fig. 7 is that the vacuum tank that enters when showing the embodiment compared using existing method and published method of the present invention takes off
The figure of the sulfur content of the one heat steel of steam stove；
Fig. 8 is when showing the embodiment compared using existing method and published method of the present invention in degassing circulation
The figure of carbon distribution in steel afterwards；And
Fig. 9 is when showing the embodiment compared using existing method and published method of the present invention in degassing circulation
The figure of sulphur content cloth in steel afterwards.
Detailed description of the invention
Fig. 1 schematically depicts the method for producing low-carbon, low nitrogen and low-sulphur steel (steel grade).In standard
During the steel for being ready for use on casting, usually, steel passes through from electric arc furnaces (EAF) to vacuum tank degasification furnace (VTD) to ladle
Metallurgical furnace (ladle metallurgical furnace) (LMF) arrives the process of casting machine (not shown).It is disclosed using the present invention
Method production steel grade have below about 0.035 weight % low-carbon.The steel grade, which also usually has, is below about 0.005 weight %
Low nitrogen and low-sulfur below about 0.003 weight % or below about 0.0015 weight %.
Steel melting factory usually has one or more electric arc furnaces, such as is equipped with 110,000,000 volt-amperes (MVA) transformer
120 tons of (metric ton) EAF.Such electric arc furnaces can have about 30~400 tons of capacity, but be typically used for the place of continuously casting
Reason amount is 60~120 tons.Each stove can contain gas injection spray gun, such as the trade mark from Praxair is Co-JetTM
Three spray gun gas injection systems, combination of oxygen and natural gas can be blown into stove by it, and also have carbon
Injection pipe.The system can be used for spraying carbon and oxygen in different proportions during entirely heating steel to manufacture foam-like
EAF clinker.In the paper Foamy Slag Fundamentals and Their of Pretorius, E.B. and R.C.Carlisle
Practical Application to Electric Furnace Steelmaking, ISS-AIME, EF Conference
Proceedings describes the preparation of foam-like clinker in 1998, pp.275-291.Top can also be installed to supply on the EAF
To flux system, lime, dolomite and carbon can be supplied by the system to control the basicity and viscosity of clinker, thus in melting
In preferably form clinker.Other converters, such as basic oxygen converter can be used in the method for the present invention.
It is in the embodiment of the method for the present invention of this description, when the oxygen content and temperature of steel compositions enter expectation
Parameter area within when, open EAF one heat steel in molten steel tapping process.Due to EAF can be separated by with VTD one section away from
From, therefore the tapping temperature of steel compositions is selected so that the temperature reduction during being transported to VTD by EAF can be VTD
In decarburization and nitrogen and sulphur decrement provide needed for temperature.It can be from stove by eccentric bottom tapping hole (EBT) system
Start to tap steel compositions into ladle, is commonly designed the system and to be brought into ladle in tapping process from EAF
Clinker minimize.For example, in the EAF of 120 tons of capacity, from stove tapping to about 105 tons of ladle of steel.
Ladle as needed is commonly installed there are two porous plug, which can be used to introduce into steel compositions
Argon.Porous plug hook (hook-up) can use to be connected automatically by corresponding ladle trunnion.The tapping work station can also
To be equipped with measuring system, the temperature of steel directly can be measured and recorded after tapping, and can measure and record and is additional
Information, such as the oxygen level in steel compositions.Once tapping process is completed, g of slag sample use can be taken out from EAF at once
To detect the FeO amount in EAF clinker.
Different from past method in the embodiment of the method for the present invention, decarburization is not completed in EAF.Instead,
In the embodiment of the method for the present invention, EAF tapping oxygen reduces in the case where corresponding higher tapping carbon level.This is improved
Method be included in the opening tapping step of converter, and in the subsequent decarbonation process of VTD.Open tapping (open
Tapping) (or (tapping open) is opened in tapping) means to tap in the case where no deliberately addition deoxidier.At this
In the embodiment of inventive method, the tapping oxygen content of steel is reduced to about 600~1120ppm, and more desirably, until about 600
~900ppm.
When VTD and converter have a distance, tapping temperature can be about 1700 DEG C~1750 DEG C, which allows temperature
Degree reduces during transporting from stove to VTD.Alternatively, when shortening the time for transporting VTD, tapping temperature can be about
1600 DEG C~1650 DEG C, or alternatively can be about 1650 DEG C~1700 DEG C.In tapping step of the invention, close argon plug from
And steel compositions can not be stirred.Once completing the tapping from stove to ladle, so that it may steel sample is taken out, and
And slag making compound, such as lime are added to cover steel in ladle, to reduce the heat loss during transporting VTD
And oxidation.Bell can preferably be placed on it before ladle transports VTD.
Compared with the conventional method, existing method is added in tapping process into steel compositions tapping step of the invention
Lime, calcium aluminate, aluminium, slag deoxidizer and ferrosilicon, and the steel compositions in ladle are carried out in entire tapping process
Stirring, so that additive be made to mix with steel compositions.In the embodiment of this method, not to steel group preferably in tapping process
Object is closed to be stirred.In addition, other than lime being added in ladle to cover steel, it can be in tapping step of the invention
It is added without flux.
Past method requires the carbon level from the EAF steel compositions tapped very low, such as less than 0.025% carbon, out
After steel, after having carried out partial desulfurization in ladle, desulfurization is subsequently completed in VTD and removes hydrogen and nitrogen.Existing
In method, average tapping temperature is 1708 DEG C.In addition, the average dissolution oxygen content (tapping oxygen) before tapping in EAF is
1398ppm, leading to the mean carbon content in ladle is 0.022%.In the conventional method, the average FeO content in clinker
It is 38.6%.In existing tapping process, FeSi, aluminium and lime joined into ladle.
In addition, in past method, aluminium dross is added in ladle to reduce reducible oxide, bring into
The concentration of the FeO and MnO of EAP clinker.Traditional EAF clinker brought into is usually less than 500kg.
In contrast, in the embodiment of the method for the present invention, in the case where being added without deoxidation additive, in a furnace
Open tapping steel compositions.As described below, tapping opening steps reduce the desulphurizing ability in the ladle before VTD.
Existing method is related to that deoxidier is added into ladle and stirs metal and clinker to provide some degree before VTD
Desulfurization.In the conventional method, before VTD step, the sulfur content of the steel compositions in ladle is usually from about 0.035 weight %
It is reduced to 0.016 weight %.
In the embodiment of the method for the present invention, after tapping step, the steel compositions in ladle are transported
To be further processed to reduce the content of hydrogen and nitrogen in VTD, and carry out the desulfurization of steel compositions.Can by delivery vehicle or
Overhead crane transports ladle.After transporting above VTD, by the mobile ladle of overhead crane and it can be placed into
In VTD tank.Once can establish the connection of VTD porous plug, just plug is opened and passes through porous plug argon is introduced into Sheng steel
In steel compositions in bucket, the flow of the argon gas used is usually less than 1m3/min.The flowing of argon causes initially to stir to broken
With liquefaction clinker, and keep the steel temperature in entire ladle more uniform.When clinker starts liquefaction, porous plug is closed, and remember
Record the measured value of temperature and oxygen amount.These measured values recorded in VTD, and in remembering in furnace before or after tapping
The measured value of record may be used to determine the alloy and flux added into steel compositions, and be used to determine the decarbonation process in VTD
Length of time.
In the embodiment of the method for the present invention, decarbonation process carries out in VTD, and deoxidation step is then carried out in VTD
Suddenly, clinker forming step, desulfurized step and nitrogen remove step.Total time ratio since there are decarburizations, in VTD work station
Existing method is about 10 minutes.But in VTD it is increased processing the time will not significantly affect steel compositions preparation it is total when
Between.
Decarbonizing process can start after closing argon stirring, and the temperature and oxygen that are recorded in the steel compositions of VTD
Amount.Bell is placed on ladle, and starts to carry out the pumping of tank.With being evacuated on ladle, gas will be from Sheng
It is removed in steel compositions in steel drum, which includes carbon monoxide (CO), hydrogen and nitrogen.Above steel compositions
CO steam drops, carbon and oxygen reaction in addition will form CO, and extract out from steel compositions.Applicants have discovered that carbon and oxygen
Reaction provides sufficient stirring action, and can not need the stirring of argon.The vacuum level used in decarbonizing process is low
In 650 millibars.In decarbonizing process, vacuum level can be about 1 millibar~650 millibars, and can be 350~550 millibars
Or it is lower than 530 millibars.
After decarburization in VTD, in the embodiment of the method for the present invention, aluminium is added into steel compositions and is used to be taken off
Oxygen.It is preferred that lime, aluminium, calcium aluminate, dolomite lime, fero-manganesesilicon (FeSiMn) to be added together, and can also be added other
Flux forms desulfurization clinker.By the uniform loading hopper of pressure, it is added and adds into steel compositions at the time of this method needs
Add agent.The aluminium added under vacuum is reactive.Before aluminium is added, vacuum level can be adjusted to about 530~1000
Millibar.
It can use process model and form required addition come the deoxidation for determining decarburization time and steel compositions and clinker
Agent.Process model can be used to control the chemical action of the clinker in VTD, this is because decarburization and deoxygenation step in VTD
It will affect the chemical action of clinker.
It can be by the composition of the clinker in the measured value and VTD of the steel compositions recorded after tapping and steel compositions
Measured value be supplied to process model (process model), or addition model (Addition Model).Adding model is one
It can be used to analyze the data of measured value or input for kind of algorithm, and compare the data and desired value or predetermined value of input.
Difference between desired or predetermined value according to the input data, addition model algorithm can determination will be into steel compositions
Which kind alloy and flux and their amount are added can promote to remove denitrification and sulphur to desired level.
The concept that addition model can use optical basicity generates better slag composition according to the capacity of sulfide.
In Sosinsky, D.J. and Sommerville, the paper The Composition and Temperature of I.D.
Dependence of the Sulfide Capacity of Metallurgical Slags, Met.Trans.B,
Vol.17B is described optical basicity concept in 1986, pp.331-337.In addition, addition model is utilized alloy and melts
The low cost combination of agent addition agent is to prepare desired composition.Addition model may be used to provide with desired steel-furnace
The fluid of slag mixed nature, caustic slag and the steel compositions through deoxidation.
In the embodiment of the method for the present invention, addition model can use algorithm to determine decarburization time, which is
In VTD after initial stirring, the algorithm of oxygen and carbon amounts in decarburization time and steel compositions is associated with based on empirical data.Addition
Model can use, and oxygen amount in VTD in the steel compositions after initial stirring determines the aluminium added after decarburization
Amount.The amount of amount and oxygen based on aluminium, since the projection (projection) of the addition model determines the fusing agent additive needed
Form desulfurization clinker.
Fixed amount can be provided to controller by adding model algorithm, which can be automatically into steel compositions
Addition determines the selected alloy and flux of amount.It is used to provide alloy to steel compositions for example, VTD can have four settings
With the hopper (bin) of flux.According to required steel compositions and slag composition, four hoppers can contain lime, aluminium, aluminium
One of sour calcium and dolomite lime or fero-manganesesilicon (FeSiMn).Controller can make by oneself each hopper activity from
And the selected alloy or fusing agent additive of measured quantity is provided into the steel compositions of the correspondingly amount of having determined that.To required
After the alloy and fusing agent additive wanted are weighed, at the time of this method needs, by the uniform loading hopper of pressure by it
Be added in the steel compositions in ladle.
In the embodiment of the method for the present invention, since from additive needed for loading hopper charging, cover is placed on its behaviour
Make in position.It closes porous plug and starts the pumping of tank.Total cycle time in VTD can be about 35 minutes.
After decarburization and deoxidation, 1~2.5 millibar of vacuum level can achieve except denitrification.
Alternatively or additionally, after desulfurization, it can achieve 1~2.5 millibar of vacuum level except denitrification.Under pumping is inhaled
Being down to 1~2.5 millibar of time is typically less than 7 minutes, and this depend partly on the thermal process of tank.Complete the removal of desulfurization and nitrogen
Time be about 20 minutes.
In the conventional method, design addition model is mainly for generation of the condition that can only remove desulfuration and nitrogen.In existing side
In method, steel compositions by part deoxidation, are deoxidized in some one heat steels to about 6.6ppm, and with about 1645 DEG C compared with
The high temperature into ladle.Since some sweetening processes occur after tapping, and during transporting VTD,
Therefore the sulfur content distribution in the steel compositions for entering VTD is irregular.Fig. 2 shows enter in the conventional method
The distribution of sulphur in vacuum tank degasification furnace.The concentration for entering the average carbon of VTD, nitrogen and sulphur is listed in Table 1 below.
Table 1: average carbon, nitrogen and the sulphur concentration of VTD are entered in existing method
| Ingredient | Concentration, weight % |
| Carbon | 0.022 |
| Nitrogen | 0.0072 |
| Sulphur | 0.016 |
As shown in table 1, in the conventional method, the concentration of carbon of steel compositions is, for example, less than within the scope of desired
0.035% carbon, directly from electric arc furnaces.As described above, this needs that steel will not be upset to be added to steel compositions in VTD
The alloy and flux of low-carbon amount in composition are selected.
Table 2: the average VTD of existing method enters the composition (weight %) of clinker
| CaO | SiO2 | Al2O3 | MgO | FeO+MnO |
| 57.8 | 5.6 | 28.4 | 7.7 | 0.5 |
In the embodiment of the method for the present invention, to steel compositions oxygen therein in the steel compositions of entrance in VTD
It measures with temperature, and is measured again after VTD circulation.Clinker and steel are also sampled after degassing circulation
Sample is to be used for chemical analysis.The aim carbon and sulfur content of steel compositions after degassing can be respectively about 0.015% peace treaty
0.0010%.Average carbon, nitrogen and the sulphur concentration for entering the steel compositions of VTD are as shown in table 3.
Table 3: average carbon, nitrogen and the sulphur concentration of VTD are entered in the method for the present invention
| Ingredient | Concentration, weight % |
| Carbon | 0.035 |
| Nitrogen | 0.0069 |
| Sulphur | 0.036 |
In the embodiment of the method for the present invention, once degassing circulation is completed to be shut off porous plug, VTD is put back into atmosphere
It is opened under pressure and by bell.At this point, sampling steel compositions and slag composition, and the temperature and oxygen of steel compositions are surveyed
It is fixed.Then as desired by overhead crane, by the steel compositions in ladle transport in ladle metallurgy furnace (LMF) with into
One step carries out alloy and heat treatment to reach the casting temperature of requirement.
The technology can be used for preparation without brilliant gap steel.The carbon level that no brilliant gap steel has can be lower than 0.01%, and
0.005% can be lower than.
In order to determine the efficiency of the method for the present invention embodiment, more following two kinds of data: utilize existing method from 500 furnaces
The previous data recorded in steel, and given birth to using the embodiment of published method of the present invention from experiments in two months of 500 furnace steel
Produce the data obtained in equipment.The data include the amount of oxygen in the steel compositions measured in tapping step, carbon and sulphur, are being gone out
The temperature of steel compositions in steel step, and the amount of the FeO in EAF slag composition.Fig. 3 show to existing method and
The comparison of the oxygen content of steel compositions between published method of the present invention.As shown in figure 3, compared with the conventional method, the present invention is public
The embodiment of the extraction of root provides lower oxygen content.Averagely tapping oxygen is reduced to the present invention from the 1398ppm of existing method
The 962ppm of method.
Fig. 4 shows influence of the lower tapping oxygen content for the FeO content of stove slag composition.Slag composition
FeO content from using the 38.6% of existing method be reduced to using published method of the present invention 27.7%.
Fig. 5 shows tapping temperature (existing method and the method for the present invention).As shown in figure 5, average tapping temperature slightly rises
Height is increased to 1724 DEG C from 1708 DEG C.It is same to provide that other decarbonation process in VTD needs slightly higher tapping temperature
VTD outlet temperature.
Fig. 6 shows lower influence of the tapping oxygen level for steel compositions carbon content, using after direct tapping from
The sample of ladle sampling measures.As shown in fig. 6, the relevant carbon content of reduced tapping oxygen content to steel compositions from
0.022% increases to 0.035%.It follows following reactions:
[C]+[O]=(CO)Gas (1)
Wherein [C], [O] and (CO)GasRespectively indicate dissolution carbon, dissolved oxygen and CO gas.According to reaction (1) institute
Show, under constant CO partial pressure, the lower dissolved oxygen content of steel compositions will lead to higher dissolution carbon content.
The sulphur that steel compositions of the existing method in the method for the present invention embodiment into VTD when are compared in Fig. 7 contains
Amount.The sulphur level of steel compositions increases average from 0.016%~0.036% when Fig. 7 shows access into VTD.Due to after tapping,
Not having sulfur transfer, therefore the distribution of sulphur becomes more regular into clinker.Present approach provides tapping opening steps, not into
The deoxidation of row steel compositions until tapping until, and in VTD carry out steel compositions decarburization.In such a situa-tion, exist
It is generally impossible to that desulfurization occurs in tapping process, this is because the removal of sulphur is driven by following reactions:
[S]+(O2-)=(S2-)+[O] (2)
Wherein [S] and [O] respectively indicates dissolution sulphur and oxygen content in steel compositions, and (O2-) and (S2-) indicate clinker
In oxygen and sulphion.High oxygen ion concentration will drive instead in low dissolved oxygen content and slag composition in steel compositions
Answer (2) to the right to carry out desulfurization to steel compositions.The deoxidation of steel compositions causes lower dissolved oxygen content de- to auxiliary
Sulphur.But deoxidation does not occur in tapping process by steel compositions prepared by the method for the present invention, so desulfurization will not be started.Separately
Outside, blast furnace basicity of slag makes the oxygen ion concentration in slag composition high, this will not appear in the embodiment party of the method for the present invention
In formula, this is because fusing agent additive is not mixed into steel compositions by the method for the present invention.Therefore, the method for the present invention is utilized
When embodiment, into VTD steel compositions sulphur level now higher than using pervious method preparation twice of steel compositions
It is more.Table 4, which summarizes, utilizes average tapping carbon, sulphur, oxygen and the temperature in existing method and the steel compositions of the method for the present invention preparation
Value.
Table 4: the summary of the tapping mean parameter of selection
Into in the vacuum tank degasification furnace of the method for the present invention embodiment slag composition and steel compositions and existing side
Method is by relatively big difference.VTD process of the present invention produces low-carbon, low-sulfur steel product.Addition model of the invention is developed to be used to calculate
Time needed for making the steel compositions decarburization to 0.015% carbon entered.Decarburization time is changed with the functional form for carbon of tapping；But it is de-
The carbon time can be about 2~5 minutes.In addition, addition model is for calculating the aluminium and silicon that make steel compositions deoxidation to required amount
The amount of manganese iron, such as after except carbon elimination, which is lower than 3ppm oxygen.The model also calculates will be with obtained deoxidation
Steel and slag composition are mixed for the lime of desulfurization and the amount of calcium aluminate.Addition model utilizes the oxygen water measured in VTD
It is flat.
Table 5 summarizes the average chemical composition of final VTD clinker (past and new method).
Table 5: average final VTD clinker composition
| CaO | SiO2 | Al2O3 | MgO | FeO+MnO | |
| Existing method | 60.5 | 6.0 | 25.2 | 7.7 | 0.6 |
| The method of the present invention | 60.4 | 7.1 | 23.5 | 8.3 | 0.7 |
Table 5 shows that embodiment by the method for the invention and existing method obtain two kinds of final slag compositions very phase
Seemingly.This shows that the steel sulphur level of the invention in the steel compositions manufactured by the method for the invention should pass through past side with those
The product that method path obtains is consistent, sulphur content cloth (LS) is defined as:
LS=(weight %S)Clinker/ [weight %S]Steel (3)
It can calculate over the sulphur content cloth of method and the method for the present invention.The L of existing methodSIt is 2100, and the method for the present invention
Embodiment LSIt is 1975.This be for sulphur content cloth it is very high, illustrate final slag composition remove and protect
Hold the effect in terms of the low levels in steel compositions.Such as Sosinsky, D.J. and Sommerville, the written The of I.D.
Composition and Temperature Dependence of the Sulfide Capacity of
Metallurgical Slags, Met.Trans.B, vol.17B, 1986, described in pp.331-337, when slag-metal system
Oxygen position (oxygen potential) known to when, can be with calculated equilibrium sulphur content cloth, or can be calculated by deoxidation equilibrium flat
Weigh sulphur content cloth.The balance sulphur breadth coefficient that equation (3) indicates temperature and optical basicity with clinker to indicate.
log LS=(21920-54640 Λ)/T+43.6 Λ -23.9-log [a0] (4)
Wherein Λ is the optical basicity of slag composition, and T is the temperature indicated with absolute temperature and a0It is steel compositions
In oxygen activity (activity of oxygen).Calculated balance sulphur breadth coefficient and measured value are carried out in table 6
Compare.
Table 6: measurement and calculated balance sulphur content cloth
| The L of measurements | Calculated balance Ls | |
| Existing method | 2100 | 2476 |
| The method of the present invention | 1975 | 2569 |
Table 6 shows that the sulphur content cloth of the embodiment of existing method and the method for the present invention is closely similar, and they are close
The balance of calculating.Ability close to calculated balance shows to make us full in the vacuum tank degasification furnace for being equipped with two porous plugs
Clinker/steel compositions mixing of meaning.
Fig. 8 and 9 is respectively illustrated in the embodiment of existing method and the method for the present invention, degassing circulation after carbon and
Sulphur content cloth.This it appears that carbon distribution is changed from Fig. 8, and the carbon that is averaged declines from 0.0245% (existing method)
To 0.0195% (the method for the present invention).In published method of the present invention, carbon amounts slightly above utilizes the addition calculated carbon amounts of model.
The present invention adds decarburization time needed for model calculates 0.015% carbon of preparation.As shown in figure 9, final sulphur content cloth becomes without obvious
Change.
It should be the result shows that can routinely produce low-carbon and low-sulfur steel compositions using method disclosed by the invention.By
Decarburization in VTD, the method for the present invention can prepare the steel grade of the low remnants of high quality, and significantly reduce oven refractory and alloy
Cost.It is per ton to save about 20 U.S. dollar of cost.Using this method, which can continue about 8 months.
It should be considered illustrative although the present invention is illustrated and described in detail in attached drawing and description above
Rather than the limitation to property of the present invention, it should be understood that preferred embodiment only has shown and described, and the invention is intended to protect
Protect all changes and modification within the scope of spirit of that invention.
Claims (16)
1. manufacturing the method with the steel lower than 0.035 weight % low-carbon, the method does not include the low-carbon comprising low-carbon FeMn
The use of ferroalloy, described method includes following steps:
(a) in converter, prepare the furnace melting steel compositions that temperature reaches tapping temperature, which is vacuum tank degassing
Temperature needed for carrying out desulfurization in furnace,
(b) oxygen level of tapping is opened as the melting steel compositions of 600~1120ppm and corresponding higher tapping carbon level to Sheng
Steel drum, wherein the temperature at 1660 DEG C~1771 DEG C is implemented to open tapping step,
(c) ladle is supplied to cover with slag making compound to form clinker on the melting steel compositions in ladle,
(d) the melting steel compositions and clinker transported in ladle are covered to vacuum tank degasification furnace, and the clinker is covered on transport
To the heat loss and oxidation for reducing melting steel compositions during vacuum tank degasification furnace,
(e) before decarburization, desired carbon content in the oxygen level and steel compositions in association melting steel compositions,
(f) decarburization is carried out to melting steel compositions by being evacuated to 350-650 millibars in vacuum tank degasification furnace,
(g) after decarburization, one or more deoxidiers are added into melting steel compositions and deoxidation is carried out to melting steel compositions,
(h) after deoxidation, one or more flux compounds are added to carry out desulfurization to melting steel compositions, and
(i) casting melting steel compositions has the steel for being lower than 0.035 weight % low-carbon to be formed,
Wherein decarburization, deoxidation and desulfurization all carry out in vacuum tank degasification furnace.
2. the method that manufacture described in claim 1 has the steel lower than 0.035 weight % low-carbon, wherein in tapping step
Carbon amounts in steel compositions is 0.02%~0.05 weight %.
3. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, wherein prepare furnace melting
The step of steel compositions, carries out in electric arc furnaces.
4. the method that manufacture described in claim 1 has the steel lower than 0.035 weight % low-carbon, wherein decarbonation process is in
350~550 millibars of vacuum level.
5. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, wherein be added it is a kind of or
The aluminium of requirement is added in the vacuum level that the step of a variety of deoxidiers is included in 530~1000 millibars.
6. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, further includes walking as follows
It is rapid: after desulfurization, to be evacuated to 1~2.5 millibar except denitrification.
7. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, wherein be added it is a kind of or
The step of a variety of flux compounds includes that the one or more compounds for being selected from lime, aluminium, calcium aluminate and fero-manganesesilicon are added.
8. the method that manufacture as claimed in claim 7 has the steel lower than 0.035 weight % low-carbon, wherein the lime includes
Dolomite lime.
9. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, wherein in tapping step
In, the sulfur content in steel compositions is 0.02%~0.06 weight %.
10. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, further includes in decarburization
Following step before step:
(i) melting steel compositions of the stirring in the ladle of vacuum tank degasification furnace,
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded,
(iii) process model is provided, the oxygen and carbon amounts and steel compositions in process model association steel compositions reach needs
Decarburization time needed for carbon amounts；And
(iv) amount based on the oxygen and carbon that measure in steel compositions, determines decarburization time using process model.
11. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, further includes in decarburization
Following step before step:
(i) steel compositions of the stirring in the ladle of vacuum tank degasification furnace,
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded,
(iii) process model is provided, the amount of oxygen and carbon in process model association steel compositions takes off with to steel compositions
The amount of deoxidation additive needed for oxygen, and
(iv) amount based on the oxygen and carbon that measure, the amount of deoxidation additive in steel compositions is determined using process model.
12. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, further includes in decarburization
Following step before step:
(i) steel compositions of the stirring in the ladle of vacuum tank degasification furnace,
(ii) temperature of the carbon amounts in steel compositions, the oxygen amount in steel compositions and steel compositions is measured and recorded；
(iii) process model is provided, the oxygen and carbon amounts which is associated in steel compositions carry out desulfurization with to steel compositions
The amount of required flux component and price based on flux component can select one or more flux components；And
(iv) amount based on the oxygen and carbon that measure determines the selection of flux component and their amount using process model.
13. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, wherein at 1660 DEG C
~1700 DEG C of temperature is implemented to open tapping step.
14. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, wherein at 1700 DEG C
~1750 DEG C of temperature is implemented to open tapping step.
15. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon, wherein at 1693 DEG C
~1771 DEG C of temperature is implemented to open tapping step.
16. the method that manufacture of any of claims 1 or 2 has the steel lower than 0.035 weight % low-carbon comprising: in (g) step
After rapid, free oxygen is added into melting steel compositions until level is that 20~70ppm and total oxygen content are at least 70ppm's
Step.
Applications Claiming Priority (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US8614108P | 2008-08-04 | 2008-08-04 | |
| US61/086,141 | 2008-08-04 | ||
| AU2008904315A AU2008904315A0 (en) | 2008-08-22 | Low cost making of a low carbon, low sulfur, and low nitrogen steel using conventional steelmaking equipment | |
| AU2008904315 | 2008-08-22 | ||
| US12/414,047 | 2009-03-30 | ||
| US12/414,047 US8313553B2 (en) | 2008-08-04 | 2009-03-30 | Low cost making of a low carbon, low sulfur, and low nitrogen steel using conventional steelmaking equipment |
| CN2009801388384A CN102171370A (en) | 2008-08-04 | 2009-08-03 | Low cost making of a low carbon, low sulfur, and low nitrogen steel using conventional steelmaking equipment |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009801388384A Division CN102171370A (en) | 2008-08-04 | 2009-08-03 | Low cost making of a low carbon, low sulfur, and low nitrogen steel using conventional steelmaking equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105714016A CN105714016A (en) | 2016-06-29 |
| CN105714016B true CN105714016B (en) | 2019-01-22 |
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| CN201610158162.7A Active CN105714016B (en) | 2008-08-04 | 2009-08-03 | Low-carbon, low-sulfur and low nitrogen steel are manufactured at low cost using traditional steelmaking equipment |
Country Status (4)
| Country | Link |
|---|---|
| CN (1) | CN105714016B (en) |
| MY (1) | MY152973A (en) |
| PL (1) | PL2331715T3 (en) |
| TR (1) | TR201820148T4 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108396094A (en) * | 2017-02-05 | 2018-08-14 | 鞍钢股份有限公司 | Smelting method of low-nitrogen low-carbon steel |
| US20250083218A1 (en) * | 2023-09-12 | 2025-03-13 | Ternium Mexico S.A. De C.V. | Process for producing clean steel with a low nitrogen content using an electric arc furnace and a degassing system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101096716A (en) * | 2006-06-26 | 2008-01-02 | 舞阳钢铁有限责任公司 | Electric furnace smelting method for high-grade pipe line steel |
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2009
- 2009-08-03 MY MYPI20110472 patent/MY152973A/en unknown
- 2009-08-03 CN CN201610158162.7A patent/CN105714016B/en active Active
- 2009-08-03 TR TR2018/20148T patent/TR201820148T4/en unknown
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101096716A (en) * | 2006-06-26 | 2008-01-02 | 舞阳钢铁有限责任公司 | Electric furnace smelting method for high-grade pipe line steel |
Non-Patent Citations (2)
| Title |
|---|
| VD生产低碳/超低碳钢的现状及在宝钢的开发前景;尹小东 等;《宝钢技术》;20050228(第1期);第35-38、52页 |
| VD精炼脱碳过程的工艺因素分析;顾文兵 等;《钢铁研究学报》;20060831;第18卷(第8期);第19-22页 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105714016A (en) | 2016-06-29 |
| TR201820148T4 (en) | 2019-01-21 |
| PL2331715T3 (en) | 2017-06-30 |
| MY152973A (en) | 2014-12-15 |
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